With respect to the above, reference is particularly made to the following publications as to relevant prior art for tire sealants which are effective in the event of damage, for example when the tread is punctured by a nail: German patent publication 26 31 691 A1 and U.S. Pat. Nos. 4,068,027; 4,113,799; and, 4,289,089.
German published patent publication 26 31 691 A1 describes a tire sealant which has a self-healing effect in the event of perforation of the tire tread. The tire sealant is based on a reinforced, partially crosslinked matrix composed of a copolymer having moderate to high molecular weight and is applied to the interior surface of rubber tires, and serves to seal perforations in the tire-tread region under a very wide variety of temperature conditions (from −30° C. to +130° C.). Solvents are used in the production of the tire sealant, examples being toluene, hexane, heptane, naphtha, trichloroethylene, cyclohexane and tetrahydrofuran.
U.S. Pat. No. 4,068,027 describes a tire sealant based on a crosslinked butyl rubber. This tire sealant is composed of two components and one of these includes the butyl rubber. These two components are mixed together shortly before introduction into the tire. The rubber component here is diluted by a solvent, such as hexane, to impart processable viscosities.
U.S. Pat. No. 4,113,799 likewise concerns a tire sealant based on butyl rubber, reinforced and partially crosslinked. It is likewise composed of two components, and here two different types of butyl rubber are used. In other respects, reference is made here to the teaching described above in German patent publication 26 31 691 A1.
Finally, U.S. Pat. No. 4,289,089 describes an apparatus for positioning, between the side walls of a tire, an operating unit which can be used to apply the tire sealant into a tire.
The process technology used hitherto for the production of tire sealants involved the use of solvents for dilution of the polymer, with the following disadvantages:                The solvents that can be used, in particular the solvents mentioned in German patent publication 26 31 691, are hazardous to the environment and to health.        Use of the solvent as auxiliary in the process generates additional material costs.        The solvents have to be removed by suction during the process and reclaimed, and there is therefore also a requirement for expensive additional steps in the process.        The solvents used hitherto created a risk of explosion during the process.        Solvents remain to some extent within the product and intermediate storage is therefore required. Associated with this, there have also been difficulties with customers' emission requirements.        